(no subject)

I was just reading through the hashcodes proposal, I see that the
proposal allows for the (remote) possibility of collisions between keys.
What jumps out at me is the potential for developers to assume that a
hashcode is the same as a unique ID (especially if some
implementations enforce uniqueness while others don't), thus leading
to subtle bugs. For that reason, I'd like to weigh in with the
opinion that requiring uniqueness for hashcodes would be really
nice. (Alternatively a separate mechanism for generating unique
object IDs would be nice.)
(I'm sure there are good reasons why enforcing uniqueness amongst
keys is a burden on implementers, although I'm unaware of what those
restrictions are. Just a layman's perspective.)
-Neil